GIS department?

[Richard Rodriguez]

I am in search of finding out the names of property owners and how many properties they may own in a particular county. I was told that I could do this via the assessors office and/or the GIS department. I don't know what GIS means but can someone please advise me how to find the owner names and to see how how many property they own?

My objective is to see who are the major investors in my area.